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FE Power Forums => FE Technical Forum => Topic started by: fe66comet on July 15, 2013, 08:51:14 AM

Title: how much HP/torque will a C4 take?
Post by: fe66comet on July 15, 2013, 08:51:14 AM
Thinking of using a C4 behind my 445 FE. How much can a C4 be built to handle in a 4/4 with big tires and a healthy engine?...... Jon
Title: Re: how much HP/torque will a C4 take?
Post by: machoneman on July 15, 2013, 08:58:12 AM
About a 1,000 hp. Most premier C-4 builders rate their top of the line trannys at/near 1,000 hp as well.

http://www.performanceautomatic.com/products/ford-racing-transmissions/c4-transmissions/
Title: Re: how much HP/torque will a C4 take?
Post by: cjshaker on July 15, 2013, 09:18:19 AM
BUT, if it's stock it won't handle it for long if you mud or do any pulling with it. 1000hp only applies to the modified ones.
Title: Re: how much HP/torque will a C4 take?
Post by: JamesonRacing on July 15, 2013, 10:37:50 AM
I'm using a Paquet C4 in my drag car with around 750hp, but that's a lot different than a 4x4.  I think I'd be looking really hard at a C6, as it should take quite a bit more beating for much less investment.
Title: Re: how much HP/torque will a C4 take?
Post by: fe66comet on July 15, 2013, 11:19:03 AM
I planned on building from scratch and using a hardened input shaft, heavy duty drum, heavy duty clutches and a modified valve body. The main issue I have is space, I am stuffing it in a Jeep Wrangler do I need something compact. I was going to use a T350 but the C4 bolts up and I have a rebuilt one already. It was converted to a Bronco II transfer case but I can get a Atlas to bolt right up. My engine is nowhere near that sort of HP so I would definitely in the safe range there. Thanks guys.......Jon
Title: Re: how much HP/torque will a C4 take?
Post by: fe66comet on July 15, 2013, 03:01:17 PM
Another question? Where do you get a high performance torque converter that has a 1.850 pilot or a bushing to 1.375 . Everything I see is 1.375 pilot for the converter......Jon
Title: Re: how much HP/torque will a C4 take?
Post by: JamesonRacing on July 15, 2013, 09:40:40 PM
I used the same converter that I had for a C6, with a simple spline adapter than several of the performance shops offer.  Another option would be to use the smaller pilot and make a simple bushing...most any machine shop should be able to knock something like that out pretty quickly.

http://www.performanceautomatic.com/products/parts-and-accessories/c4-race-parts/c4-spline-adapter.html
Title: Re: how much HP/torque will a C4 take?
Post by: hbstang on July 16, 2013, 07:14:15 PM
i think jay may have some input on this.wasnt his galaxie that he ran in drag week equiped with a c4?i have a very good friend who has been doing trans work for 40 years,and hes a ford guy.his name is dana sniff,hes in irvine ca.he is on face book if you want to look him up.he built a c4 that ran 4th in class in the baja 500 recently.
Title: Re: how much HP/torque will a C4 take?
Post by: fe66comet on July 16, 2013, 09:38:10 PM
I found converters from performance automatics that have big or small pilots for C4s. Also the bell housing to hook it up, pricey but it is a better option than A T350 or C6 as it is the smallest and shortest of the bunch. In order to build it bullet proof and bolt in it will run a little over 2700 with the starter and adapter to an Advance Adapter Atlas four speed transfer case. It does guarantee no breakage at my power level to have the Pro Max rebuild kit, roller bearing conversion, six pinion planetary set, Pro pump, hardened input shaft and six clutch high gear drum. Also going with a 2500-3000 stall converter and heavy duty flex plate with the Bell housing kit. I was told by Performance Automatics this would give me a 60% easy boost in strength and greatly improve torque output at the rear wheels.....Jon
Title: Re: how much HP/torque will a C4 take?
Post by: jayb on July 16, 2013, 09:49:05 PM
i think jay may have some input on this.wasnt his galaxie that he ran in drag week equiped with a c4?i have a very good friend who has been doing trans work for 40 years,and hes a ford guy.his name is dana sniff,hes in irvine ca.he is on face book if you want to look him up.he built a c4 that ran 4th in class in the baja 500 recently.

My Galaxie does have a C4, and it is no small feat for a C4 to live behind a 900+ HP SOHC in a 3900 pound car on slicks LOL!  Unfortunately automatic transmissions are something I'm just not all that knowledgeable about.  I know that the trans in the Galaxie has cryo-treated input and output shafts, red clutches, and a Performance Automatics valve body and servo valve.  Other than that, its pretty much a mystery to me.
Title: Re: how much HP/torque will a C4 take?
Post by: fe66comet on July 17, 2013, 11:55:35 AM
Sounds like the.same deal they recommended for me, what kind of shifters are you guys running? I had a B&M cable shifter, it worked well except I went though burned cables on the exhaust. Then I had a lokar with mechanical linkage that is mounted to the top of the trans housing on my T350. It placed the shifter in the perfect spot but all the C4 shifters appear to be mounted on the tail shaft or the floor, I will have a transfer case and that is way too far back for where I need it. The floor mount has me concerned about linkage movement and bind in rough terrain. Any ideas guys? Thanks......Jon
Title: Re: how much HP/torque will a C4 take?
Post by: rockhouse66 on July 17, 2013, 04:24:25 PM
This is the C4 setup that came in the Mustang I bought.  The cable makes a U-turn behind the shifter tower and then goes forward under the floor.  Maybe you will recognize the components?

Title: Re: how much HP/torque will a C4 take?
Post by: fe66comet on July 17, 2013, 04:31:03 PM
Kinda hard to see in the pick but looks like a TCI Quarter stick to me. Full competition just like your car, I dig the interior it has nice metal work..... Jon
Title: Re: how much HP/torque will a C4 take?
Post by: rcodecj on July 19, 2013, 01:43:42 PM
I am under the impression that for the C4 to handle 1000 hp it would have to be a full manual valve body.
Does anyone know how much hp they will take with a regular valve body (leave it in drive, car shifts itself)?
I like the idea of using a C4 but I want to leave it in drive when I drive it or race it, and also just use the factory shifter.

Title: Re: how much HP/torque will a C4 take?
Post by: jayb on July 19, 2013, 10:09:57 PM
I think it is correct that a manual valve body is required for really high horsepower from a C-4.  I think Performance Automatic told me that their non-manual C-4s were good for 750 HP.  In fact, when I first put the C-4 in my Mach 1 it had the normally shifting valve body, and the engine was the 706 HP 511" FE that I ran at Drag Week in 2005.  I had the same thoughts as you; I didn't want to mess with manually shifting the trans.  But I never could get the transmission to shift right, and in the end it turned out that the engine just didn't have enough vacuum for the vacuum modulator on the transmission to work properly.  So sometime during the summer of 2005 I swapped my valve body out for the manual version.  Shifting manually turned out to be no big deal, and I have never thought of going back to an automatic shift on that car, or any of my automatic cars.  Also, I have been able to retain the stock shifter; it requires a  certain touch on the track, but again I was able to get used to it pretty quickly.

In short, I wouldn't let the requirement for a manual valve body keep you away from the C-4...
Title: Re: how much HP/torque will a C4 take?
Post by: lovehamr on July 21, 2013, 07:20:46 AM
These must be some quite modified c4's because with a couple of early mustangs I got to where I could swap one in an hour just because I did it so often.  This was behind only slightly warmed over small blocks.
Title: Re: how much HP/torque will a C4 take?
Post by: manofmerc on July 27, 2013, 05:54:31 AM
The best info I have seen on the internet about high hp c4s is on the 429 460 forum .A lot of street racers drag racers have their comments and buildups on there.And some of them are running 545s not 445 cu.in. . Most drag racers use a c4 for quicker et.s and that is always the case .Going from a c6 which is heavy to begin with to a much lighter c4 is a huge benefit .And then you have the lighter internals and probably less friction as well  .Unless you plan to drag race your truck I would go with a c6 .Less expense and less maintenance and it will hold up to a lot of abuse .A good valve body 5 clutchs in the high gear drum and thats about all you need .But for some real world info go to the 429460 forum click onto driveline lots of c4 stories there .I am just partial to c6s .I have three in my cyclones that I built myself and I am just familar with them .Nothing wrong with a good c4 Doug 8)
Title: Re: how much HP/torque will a C4 take?
Post by: machoneman on July 27, 2013, 07:15:18 AM
I like the C-6 as well but most over on the 460 Forum use the C-4 for one big reason: one gains about 30 hp due to less internal parasitic drag than a C-6

http://www.460ford.com/forum/archive/index.php/t-118570.html
Title: Re: how much HP/torque will a C4 take?
Post by: jayb on July 27, 2013, 08:29:54 AM
I like the C-6 as well but most over on the 460 Forum use the C-4 for one big reason: one gains about 30 hp due to less internal parasitic drag than a C-6

http://www.460ford.com/forum/archive/index.php/t-118570.html

That's a fact, and you can really feel the difference.  When I swapped the C-6 out of my Mach 1 for the C-4 back in 2005, with no other changes it felt like somebody had released a dragging emergency brake on the car.  Night and day difference.
Title: Re: how much HP/torque will a C4 take?
Post by: turbohunter on July 27, 2013, 09:58:12 AM
Is there a way to have a C6 gone through to help that sitch out? Or is the large parasitic loss inherent in the design and unfixable?
Title: 1300HP Grab the Sept Race Pages or wait a month till it shows up on line.
Post by: Qikbbstang on July 27, 2013, 10:06:07 AM
 NMRA forbids Powerglides in numerous classes.  The say the c4 will handle 1300HP and seriously  detail all the guts/mods to do it
Title: Re: how much HP/torque will a C4 take?
Post by: machoneman on July 27, 2013, 10:30:17 AM
In a word, no.

I'll try and find a direct answer to that from a racing tranny shop (Art Francis? TCI?) I had contacted concerning the CC article via the other Forum long ago. The owner IIRC stated that the mere weight of all a C-6's internals (flywheel effect) versus a C-4's, or a "Glide for that matter, is what primarily causes the hp loss. Valve body operation, fluid routing and a few other things also contribute to the larger hp loss, none of which IIRC compare closely to the weight or the internal components.  Kelly's site has some C-4/C-6 details:   http://raceabilene.com/kelly/hotrod/trans.html

On edit: just remembered that the tranny expert also stated that the 'Glide has the absolute lowest weight of all rotating components (re: stock parts, all were tested w/o convertors) of all the trannys mentioned in the CC test. Not surprising then that it has the lowest parasitic drag.